The first two years of this study were designed to determine the feasibility of a longer study to determine whether clinically and statistically a difference in level of blood glucose control can be achieved between standard and experimental therapy groups. This feasibility study was successfully completed in September, 1985, and the long term trial is now well underway in 27 centers. The long term trial will compare the effects of intensive vs. standard glycemic management on retinopathy and other endpoints in IDDM.